Our subjective feeling of hot and cold depends on the rate at which heat is lost through our skin. In this problem, we will model the skin as a flat layer of fatty tissue (k 0.3 W/m °K) with a thickness of 4 mm, separating an environment with a constant temperature of 37°C (normal body temperature) and the outside air. On a calm winter day with an ambient temperature of 0'°C, the convective heat transfer coefficient between the skin and the ambient air is approximately equal to 20 W/m2 °K. Find the heat flux lost through the skin.